The Cupertino company has recently filed a patent application for a new invention known as “Subtractive Display”, which describes a display making use of the print-oriented CMY colour system instead of RGB.

Read on to find out more.

For those who deal with design and photography, the LCD monitor can sometimes be more of more of a liability than an asset, especially if the end-result has to be sent out for printing. And for good reason: all monitors make use of a additive combination of red, green and blue subpixels (hence the term RGB) to reproduce colours of the visible spectrum at varying intensity.

However, the problem lies in the fact that colour printers use a subtractive cyan-magenta-yellow colour model which produces a much narrower range of colours than what RGB is capable of. So, if you were to send out a file with an RGB colour profile over to a printer for spooling, chances are what you’ll see on print is usually no where near as accurate or vibrant as what was displayed on your screen. Add that to the fact that most screen today come with a glossy finish which artificially saturates the colours onscreen, and you get a display which is completely unsuitable for any serious screen-to-print design work.

Of course, this is a well-known issue among professional designers and photographers, and the current solution to this problem is simple: simply have the software change the colour profile of the project from RGB to CMYK before saving the file and sending it out for printing. But even then, the colour conversion may not always be entirely accurate, and one might find that the resulting printout will still retain some degree of colour discrepancy.

Fortunately, it seems that Apple has decided on what it perceives is the best method for eliminating this issue once and for all, and that is to simply make a display that produces colours in CMYK instead of RGB.

According to the patent application filed by Apple, such a display can be achieved by replacing the RGB subpixels with adjustably subtractive light filters to generate the required combinations of cyan, magenta and yellow. Add that to some proper colour calibration of the monitor, and it would theoretically result in the most print-accurate colours being reproduced onscreen, thus eliminating the need for designers to convert their RGP colour profiles into CMYK.

Of course, favouring CMY over RGB does come with its own set of issues, and we’re expecting that the biggest problem most people will have with such displays is its greatly reduced ability to replicate more colours of the visible spectrum. However, Ars Technica has pointed out that this might actually be a non-issue, as even the best RGB displays , with their theoretical potential to generate “some 16.7 million combinations of hue and intensity”, usually end up falling short of that number by a huge margin.

And even if Apple’s CMY displays were to be sorely lacking in colour variety, it should be noted that the only people who would consider getting CMY displays will be a very specific subset of professionals which rely on paper-accurate colour reproduction as part of their livelihood. In other words, it’s not something that will be targeted at the common end-user, which would make a lot more sense.